Bioleaching of Phosphorus from Low Grade Ores and Concentrates with Acidophilic Iron- and Sulphur-Oxidizing Bacteria

2013 ◽  
Vol 825 ◽  
pp. 266-269 ◽  
Author(s):  
Tuija H. Sarlin ◽  
Outi K. Priha ◽  
Mona E. Arnold ◽  
Päivi Kinnunen
Keyword(s):  
Energy Source ◽  
Acidithiobacillus Ferrooxidans ◽  
Elemental Sulphur ◽  
Phosphorus Leaching ◽  
Low Grade ◽  
Sulphide Minerals ◽  
Bacterial Cultures ◽  
Acid Generation ◽  
Phosphorus Extraction ◽  
Shake Flasks

Bioleaching experiments of phosphorus from low grade fluorapatite ore containing 8.2% P2O5 and from fluorapatite concentrate containing 29.8% P2O5 were carried out in shake flasks. Elemental sulphur was supplemented as an energy source for acid generation. Mixed and pure acidophilic bacterial cultures consisting of iron-and/or sulphur-oxidizing bacteria Acidithiobacillus ferrooxidans, A. thiooxidans and Leptospirillum ferrooxidans were used in the experiments. These acidophiles are commonly used in bioleaching of sulphide minerals, but their application on phosphorus bioleaching has been limited. Phosphorus leaching was shown to be a pH-dependant phenomenon. Phosphorus leaching yields of up to 97% and 28% were obtained in 3 weeks for low grade fluorapatite ore and concentrate, respectively. These results indicate a potential for applying bioleaching for phosphorus extraction from low grade materials.

Depression of pyrite in the flotation of high pyrite low-grade lead–zinc ore using Acidithiobacillus ferrooxidans

2010 ◽  
Vol 23 (1) ◽  
pp. 10-16 ◽  
Author(s):  
J.V. Mehrabani ◽  
M. Noaparast ◽  
S.M. Mousavi ◽  
R. Dehghan ◽  
E. Rasooli ◽  
...  
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Low Grade ◽  
Lead Zinc

Microbial Populations in a 110 Ton-Scale Column for the Recovery of Metals from Black Schist Ores

2007 ◽  
Vol 20-21 ◽  
pp. 170-170 ◽  
Author(s):  
Kevin B. Hallberg ◽  
D. Barrie Johnson ◽  
Jörg Langwaldt ◽  
Catherine Joulian
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Large Scale ◽  
Sulfide Minerals ◽  
Total Cell ◽  
Microbial Populations ◽  
Low Grade ◽  
Cell Counts ◽  
Solid Media ◽  
One Year ◽  
Black Schist

Black schist ores in Finland are often enriched with sulfide minerals, containing a variety of base metals such as nickel, copper, zinc and cobalt. As these ores are low grade with respect to the metals contained and the sulfide minerals cannot be effectively concentrated from the schists, they are currently being studied with regard to their suitability for bioleaching [1]. As part of this investigation, a large-scale column measuring 3 x 3 x 9 m was built and filled with 110 tons of the crushed black schist ore. A solution was circulated in the column for 95 weeks; this solution was adjusted to 1.8 prior to entry in the column and averaged 2.7 when leaving the column. During this time, approximately 22% of Mn, 10% of Ni and 5% of Zn were leached from the ore. Iron was also leached, but precipitated in the column. Any soluble iron in the effluent was mainly Fe (II). During this same time period, total cell counts averaged 3.6 x 107 cells/ml of effluent. On three different occasions over nearly a one-year period, culturable cells were enumerated on a variety of solid media [2] and represented only about 1% of the total cell counts. Of the culturable cells, ironoxidizing acidophiles (namely Acidithiobacillus ferrooxidans) far outnumbered any other acidophile by at least a factor of ten. Changes in populations were also monitored by molecular means (T-RFLP and SSCP) on five different occasions during the same year; again, populations in early samples were dominated by Acidithiobacillus ferrooxidans (at least two strains/sub-species). As the temperature of the column was increased from ~20 to 35°C by heating both the recirculated liquor and the air used for column aeration, the relative abundance of At. ferrooxidans-like bacteria decreased while the abundance of unidentified bacteria increased. Some of these bacteria have also been detected in lab-scale column experiments using the same ore [3]. Total cell counts varied little as the temperature increased, nor was there any change in the rate of metal leaching. It was apparent that even though the leaching of metals from black schist ores was not greatly influenced by increases of temperature in the column, active microbial populations were present and were influenced by temperature.

Improved Phosphate Ore Leaching with Physical Mutagenized Acidithiobacillus Ferrooxidans Based on Modified Logistic Model

2012 ◽  
Vol 214 ◽  
pp. 520-524 ◽  
Author(s):  
En Wen Wang ◽  
Shao Min Lei ◽  
Wen Qi Gong
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Treatment Time ◽  
Ph Value ◽  
Hot Spring ◽  
Temperature Treatment ◽  
Low Grade ◽  
Initial Growth ◽  
Illumination Time ◽  
Phosphate Ore ◽  
Low Temperature Treatment

Strains of Acidithiobacillus ferrooxidans (At.f) were separated and purified from water sample collected from a hot spring and bioleaching a low grade phosphate ore. The results indicated that bioleaching phosphorus rate increasing sharply was starting at the ending of pH value decreasing, and ascend velocity had slowed down after linear regression of pH was at its second peak. In the environment of ultraviolet mutagenesis, the initial growth of At.f (r) was decreased by illumination time increased, but the maximum rate of bioleaching phosphate ore (ηm) was increased. In the condition of ultrasonic vibration, r was increased by vibration time added, and ηm was almost increased, except 20 min, owing to the modificatory coefficient was large enough. In circumstances of low temperature treatment, r was decreased by treatment time raised; ηm was more increase than the sample of un-treatment (CK).

Attachment of Acidithiobacillus ferrooxidans and Bioleaching of Chalcopyrite under Influence of Organic Substances Associated with Copper Solvent Extraction

2017 ◽  
Vol 262 ◽  
pp. 75-78 ◽  
Author(s):  
Xiao Rong Liu ◽  
Hao Zhang ◽  
Hua Long Yu ◽  
Yan Hao Zhu
Keyword(s):  
Solvent Extraction ◽  
Acidithiobacillus Ferrooxidans ◽  
Low Grade ◽  
Organic Substances ◽  
Copper Solvent Extraction ◽  
Influence Of Solvent

Small quantities of organic substances are inevitably entrained and dissolve in the aqueous raffinate during a copper solvent extraction (SX) operation. These organic substances contaminate the bioleaching environment through the loopback of the raffinate. The attachment of cells of Acidithiobacillus ferrooxidans (At. ferrooxidans) to the low grade chalcopyrite ores and the bioleaching of the ores under the influence of solvent extraction organic substances were investigated. The results showed that the cells of At. ferrooxidans were apt to attach on the SX organics-contaminated chalcopyrite ores with an adsorption ratio of about 83%, larger than that of 44% on the uncontaminated ores as a control. However, the bioleaching efficiency decreased from 25% to 15% under the influence of the SX organic substances. Obviously, an improvement of the cells attachment did not improve the bioleaching efficiency of the low grade chalcopyrite ores by At. ferrooxidans in the present of the SX organic substances. The SX organic substances impacted the metabolism of At.ferrooxidans and their bioleaching ability.

Characterization of the Quorum Sensing Regulon in Acidithiobacillus ferrooxidans

2013 ◽  
Vol 825 ◽  
pp. 129-132 ◽  
Author(s):  
Sigde Mamani ◽  
Yan Denis ◽  
Danielle Moinier ◽  
Mohamad Sabbah ◽  
Laurent Soulère ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Quorum Sensing ◽  
Acidithiobacillus Ferrooxidans ◽  
Operating Cost ◽  
Second Step ◽  
Low Grade ◽  
Mineral Surface ◽  
Homoserine Lactones ◽  
The Moment

Bioleaching is the solubilization of metals from ores by microorganisms. This process is more efficient than conventional methods in the metal recovery from low grade ores while decreasing the operating cost and the environmental impact. Among the bioleaching bacteria, the Gram-negative chemolithoautotrophic acidophilic Acidithiobacillus ferrooxidans has the ability to adhere to mineral surface and to form biofilm. The genes involved in the production of this biofilm are controlled by a cellular communication system called Quorum Sensing (QS). The QS occurs mainly through the production of acyl homoserine lactones (AHLs). A functional QS system has been identified in At. ferrooxidans with an acyl synthase (AfeI) and a transcriptional regulator (AfeR). Here, our purpose is to characterize the quorum sensing regulon and particularly the genes involved in biofilm formation in At. ferrooxidans. This has been done by cell adhesion experiments comparing At. ferrooxidans grown with or without Tetrazol, an AHL analogue that activates the cell adhesion to mineral surface. The second step has been to compare the expression of some genes predicted to be involved in the QS regulon in At. ferrooxidans grown in the presence/absence of Tetrazol using real-time PCR. These two different strategies are expected to give insight on the moment at which the At. ferrooxidans QS regulon is switched on. The formation of biofilm could improve the bioleaching operation and therefore the understanding of the QS regulon is of primordial importance.

scholarly journals A comparative study on psychrophilic and mesophilic biooxidation of ferrous iron by pure cultures of Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivorans

2020 ◽  
Vol 99 (3) ◽  
pp. 128-133
Author(s):  
K.N. Seitkamal ◽  
◽  
Nariman Zhappar ◽  
Valerij Shaikhutdinov ◽  
Aigerim Shibaуeva ◽  
...  
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Sulfate ◽  
Ferrous Iron ◽  
Mine Drainage ◽  
Important Process ◽  
Sulphide Ores ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Pure Cultures ◽  
Shake Flasks

Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivoransis an important process in the bioleaching of minerals and the treatment of acid mine drainage. The rate at which biooxidation reactions take place is directly related to the microorganisms’growth temperature. Decreasing the temperature of reaction causes both a decrease on the chemical reactions rates and a decrease on bacterial growth. In this study, the effects of pH and temperatures on oxidation of ferrous sulfate by a native At. ferrooxidans and At. ferrivorans strains were investigated. The biooxidation tests conducted in shake flasks at 28 °C and 8 °C and at initial pH 1.6 for 5 days. During the experiment, the mesophilic iron oxidizers were capable of growing on ferrous iron at concentrations of 4.5 g/L at low and optimum temperature. However, the rate of mesophilic biooxidation of ferrous iron was higher than that observed in the psychrophilic biooxidation. In conclusion, during the experiment the At. ferrivorans strain 535 showed high activity in oxidizing at low temperature than other strains. It means even at very low temperatures, microorganisms play an important role in the oxidation and leaching of sulphide ores.

Sign in / Sign up

Export Citation Format

Share Document